TeX:
\pi = 2 \sum_{n=0}^{\infty} \operatorname{atan}\!\left(\frac{1}{F_{2 n + 1}}\right)Definitions:
| Fungrim symbol | Notation | Short description |
|---|---|---|
| Pi | The constant pi (3.14...) | |
| Sum | Sum | |
| Atan | Inverse tangent | |
| Fibonacci | Fibonacci number | |
| Infinity | Positive infinity |
Source code for this entry:
Entry(ID("31eecc"),
Formula(Equal(Pi, Mul(2, Sum(Atan(Div(1, Fibonacci(Add(Mul(2, n), 1)))), For(n, 0, Infinity))))))